NICKEL AND COBALT. 



169 



CoO. 



78.591 1 

 78.588 I 



78.550 j- 1st sample. 



78.598 I 



78.614 J 



78.603 



78.591 



78.591 



78.588 ^ 



78.592 / 

 78.597 



2d sample. 



■ 3d sample. 



75.597 1 



78.598 } 4'^^ '""^P^^- 



78.595 



78.589 [ 5th sample. 



78.596 



Mean of all, 78.592, ± .0023 



These percentages are practically identical, and lead to 

 essentially the same mean value for each atomic weight. 



In a later paper Russell* confirmed the foregoing results 

 by a different process. He dissolved metallic nickel and 

 cobalt in hydrochloric acid and measured the hydrogen 

 evolved. Thus the ratio between the metal and the ulti- 

 mate standard was fixed without the intervention of any 

 other element. About two-tenths of a gramme of metal, or 

 less, was taken in each experiment. 100 parts by weight of 

 Co or Ni give the following weights of H, calculated from 

 the volume of the latter : 



Ni. 



420 1 

 418 I 



416 I 



417 )■ ist sample. 

 412 



415 

 416 j 



Co. 



3-395 

 3-398 

 3-397 

 3-398 

 3-403 

 3.401 



3-401 



1st sample. 



2d sample. 



■ Joum. Chem. Soc, (2,) 7, 494. 1869. 



